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dc.contributor.authorWu, Xingyi
dc.date.accessioned2017-12-07T10:00:40Z
dc.date.available2017-12-07T10:00:40Z
dc.date.issued2017-12-01
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/270012
dc.description.abstractGraphene is a two dimensional carbon material whose outstanding properties have been envisaged for a variety of applications. Cu-catalyzed chemical vapour deposition (Cu-CVD) is promising for large scale production of high quality monolayer graphene. But the existing Cu-CVD technology is not ready for industry-level production. It still needs to be improved on some aspects, three of which include synthesizing industrially useable graphene films under safe conditions, visualizing the domain boundaries of the continuous graphene, and understanding the kinetic features of the Cu-CVD process. This thesis presents the research aiming at these three objectives. By optimizing the Cu pre-treatments and the CVD process parameters, continuous graphene monolayers with the millimetre-scale domain sizes have been synthesized. The process safety has been ensured by delicately diluting the flammable gases. Through a novel optical microscope set up, the spatial distributions of the domains in the continuous Cu-CVD graphene films have been directly imaged and the domain boundaries visualised. This technique is non-destructive to the graphene and hence could help manage the domain boundaries of the large area graphene. By establishing the novel rate equations for graphene nucleation and growth, this study has revealed the essential kinetic characteristics of general Cu-CVD processes. For both the edge-attachment-controlled and the surface-diffusion-controlled growth, the rate equations for the time-evolutions of the domain size, the nucleation density, and the coverage are solved, interpreted, and used to explain various Cu-CVD experimental results. The continuous nucleation and inter-domain competitions prove to have non-trivial influences over the growth process. This work further examines the temperature-dependence of the graphene formation kinetics leading to a discovery of the internal correlations of the associated energy barriers. The complicated effects of temperature on the nucleation density are explored. The criteria for identifying the rate-limiting step is proposed. The model also elucidates the kinetics-dependent formation of the characteristic domain outlines. By accomplishing these three objectives, this research has brought the current Cu-CVD technology a large step forward towards practical implementation in the industry level and hence made high quality graphene closer to being commercially viable.
dc.description.sponsorshipCambridge Trust Scholarship St John's College Overrun Funding Cambridge Hardship Funding
dc.language.isoen
dc.rightsNo Creative Commons licence (All rights reserved)
dc.subjectgraphene
dc.subjectchemical vapour deposition
dc.subjecttwo dimensional material
dc.subjectlarge scale synthesis
dc.subjecteletron mobility
dc.subjectthin film characterization
dc.subjectgraphene domain boudnaries
dc.subjectscalable and nondestructive visualisation
dc.subjectgrowth kinetics
dc.subjectquantitative modelling
dc.subjectnucleation kinetics
dc.titleCU-CATALYZED CHEMICAL VAPOUR DEPOSITION OF GRAPHENE: SYNTHESIS, CHARACTERIZATION AND GROWTH KINETICS
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentDepartment of Engineering
dc.date.updated2017-12-06T15:54:33Z
dc.identifier.doi10.17863/CAM.16855
dc.publisher.collegeSt John's College
dc.type.qualificationtitlePhD in Engneering
cam.supervisorRobertson, John
rioxxterms.freetoread.startdate2017-12-06


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